Metal clad insulating floating roof



NOV. 25, 1958 D, D, GRAsslCK l 2,861,713

METAL CLAD INSULATING FLOATING ROOF' /4/5' A 7702 New.

Nov. 25,1958 D. D. GRAsslcK 2,861,713

METAL CLAD INSULATING FLOATING ROOF' Filed July 20, 1956 2 Sheets-Sheet 2 INVNTOR.

United States Patent' METAL CLAD INSULATING FLOATING ROOI?` Donald D. Grassick, Chicago, Ill., assignor to Universal Fabricated Products Co., Chicago, Ill., a corporation of Illinois Application July 20, 1956, Serial No. 599,233

3 Claims. (Cl. 220-26) My invention relates to new and useful improvements in a metal clad insulated floating roof and has for its principal object the provision in a device of this character of an improved construction consisting of Prefabricated insulated paneled roof sections for sewage digestion tanks.

Another object of my invention is the provision of an apparatus of this character wherein the floating roof is semicxible and has self-load distributing features.

Still another object of my invention is the provision of an apparatus of this character wherein the paneled metal clad roofing sections embody high thermal insulation properties.

Yet another object of my invention is the provision of an apparatus of this character in which there is a means for effectively providing detachably connections between the insulated panel sections and a basic roof structure.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to -the tank. To accomplish this, I provide a s-teel discshaped cover 10. This cover 10 is of a diameter suicient in size to freely pass between the vertical Walls of the tank 11, thereby permitting vertical movement of the cover so as to conform to the contents of sewage within the tank 11. The center of the cover forms a vertically disposed gas collecting chamber 12. This chamber 12 has open communication with the interior of the tank 11 and is air-sealed at the top by a metal piece 13.

The peripheral edge 14 of the cover 10 is extended in a vertical direction so as to form the cover 10 into a substantially panlike structure.

Within this panlike structure there are tted structural members in the form of horizontal and substantiallydiagonally extending steel trusses 15 and 15', respectively, as shown in Fig. 3. The trusses 15 extend in a radial direction from the gas chamber 12 to the vertical peripheral edge 14 of the cover 10 asviewed in Figs. 2 and 3.

Between the trusses 15 are steel purlins 17 of various lengths depending on their placement with respect to the distance between the radially extending trusses 15. In providing a Weatherproof semi-flexible upper roof structure for the tank 11, I employ prefabricated roof sections 16, Ias shown in Fig. 4.

These roof sections 16 comprise a top metal plate 18, a bot-tom corrugated plate 19, and an insulation plate filler 20; to separate the plates 18 and 19, Ipprovide spacer members 21. In order that the spacer members 21 do not act as a heat conductor between the plates 18 and 19, I position insulator block 22 between the member 21 and its connection to the plate 19. At this connection, the member 21 is fastened to the plate 19 by a sheet the accompanying drawings showing the preferred form of construction, and in which:

Fig. 1 is a perspective view of a sewage digestive tank with which my improved floating roof is associated;

Fig. 2 is a sectional detail view taken on line 2 2 of Fig. l, showing the internal construction of the sewage digestion tank;

Fig. 3 is a fragmentary sectional view of the tank and roof section;

Fig. 4 is a side elevational View of one insulated panel roof section;

Fig. 5 is a fragmentary side sectional view of an insulated panel section;

Fig. 6 is a fragmentary detail view of the panel overlap feature and steel truss structure;

Fig. 7 is a fragmentary detail view of the panel clip and steel purlin structure; i Y

Fig. 8 is a fragmentary detail sectional view of the roof panel connecting means as associated with the peripheral edge of the basic roof structure;

Fig. 9 is a fragmentary detail sectional view of the roof panel mounting to the vertically disposed gas collecting chamber.

This invention relates to a floating sectional cover for sewage digestion tanks which make uppart of a sewage disposal unit. The overall construction of such tank is shown in'Fig. l. The sewage contents of the tank, while undergoing liquefaction or purification, is maintained atpvarious levels within the tank and must be under cover at all times. The optimum temperature of operation is in the range o-f 90 to 100, and the process is more satisfactorily accomplished when the upper surface of the sewage contents of the tank is not directly exposed to the air or air circulation. It is to overcome this air circulation that oating tank covers are employed. f

My improved cover is supported upon the contents o metal screw 19 or the like. v

The panel section 16 has one end and one side thereof provided with an overlap portion 24. This portion 24, as viewed in Figs. 4 and 5, is an extension of the top plate 18. The overlap portion 24 is fastened to the next succeeding panel section by sheet metal screws 26 or the like, as shown in Fig. 6. Such overlap construction and connection makes a waterproof junction between the panel sections 16 when formed together to make the upper roof section fo-r the tank 11.

To attach the panel section to the purlins 17 I provide the underside of the panel sections with socket-providing clips 27. The sockets of these clips 27 frictionally re# ceive a flange member of the purlin 17, `as viewed in Fig. 7. Such construction and arrangement of the parts provides a detachable connection between the cover 10 and the upper roof sections 16.

In Fig. 8 I show the method of connecting the roof panels 16 to the vertical peripheral edge 14 of the cover 10. To do so, I fasten to the inner side of the peripheral edge 14 an angular 'purlin 17. To the tcp plate 18 of the panel sections 16 I'fasten a depending angle bar 28. The corrugated plate 19 rests on the angled purlin 17', and the depending angle bar 2S is placed to the cuter side of the vertical peripheral edge 14 of the cover 10 as viewed in Fig. 8. Such depending angle bar 28 and the vertical peripheral edge 14 are then fastened together to maintain a weather seal between the cover 10 and the upper roof structure made up of the panel sections 16.

kTo provide a weather seal between the cover 10 and the Ywalls 11 of the tank, I provide a resilient inverted U-shaped sealer piece 29 as viewed in Figs. 2 and 3. This sealer piece 29 prevents moisture of any form from seeping into the tank 11. Such sealer piece 29 extends around the peripheral edge of the cover 10 and the side wall of the tank 11 and may be provided with any type of suitable drain (not shown).

To provide a seal between the panel section 16 and th gas collecting chamber 12, I provide an open end socket about the peripheral wall of such chamber 12. As shown in Fig. 9, this socket is formed by providing a circular angled end 30 `on the wall of the chamber 12. The flange of such member 30 is slopedin a downward direction so as to maintain proper drainage thereof. Spaced from such member 3@ is a horizontally extending circular plate 31. This plate 31 is adapted to be received in the socket formed by the clips `27carried by the corrugated bottom plate 19 of the panel sections 16, as viewed in Fig. 9. By such arrangement and construction there is established a semi-flexible weatherproof connection between the panel-structure 16 and the vertically disposed gas collecting chamber 12.

It should be noted that the trusses and purlin framework on which are positioned the panel sections, are sloped downwardly from the center gas collecting chamber'12 toward the outer vertical peripheral edge 14'of the cover 10. When the panels .16 are placed upon the truss and purlin framework, they will assume the same slope, as all the panels have overlaps, and as the gas collecting chamber 12 is provided with a waterproof connecting means .with the sections 16, it is readily apparent that a Hoating roof such as constructed in the above described manner provides an eicient method of draining off moisture collected thereon through atmospheric conditions.

` When all the panel units are secured in position the outer roof covering forms in effect a one-piece roof suficiently ilexible to withstand distortion without alfecting the joints between the panel sections 16. This floating roof presents a smooth permanent outer Weatherproof protective covering for the tank 11. The insulation core 20 provides high thermal insulation for the preservation of the optimum processing temperatures. The corrugated bottom cover plates 19 support the load and transmit the same uniformly to the truss andpurlin structures. The clips 27, while holding the panels to the truss and purlin structures, permit sucient iiexibility of theroof and thereby lavoid concentrated ystrain or breaking points.

The whole metal clad insulated upper roof structure will therefore accommodate itself to movement incident to the various levels of the sewage contents of the tank 11.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. I, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. A floatable roof for sewage digestive tanks comprising a substantially horizontally extending cover, said cover having a vertically extending peripheral edge, a vertically disposed gas collectingchamber atthe center of said roof and having open communication with said tank, an upper roof structure carried by said cover in spaced confronting relation, said upper roof structure consisting of a plurality of prefabricated panel sections each comprising a top plate and an inner load carrying bottom plate, means for spacing said top plate and said bottom plate in a parallel plane with respect to each other, insulation means carried between the top plate and the bottom plate, the said top plate being of a size greater than said bottom plate so as to provide an over-lapping portion along one side and bottom edge thereof, saidoverlapping portion providing a cover for the connection points between said panelled sections structural trusses carried by said cover for supporting said upper roof structure in spaced floating relation, means carried by said upper roof structure for detachably connecting itself to said structural trusses, and means on said vertically extending peripheral edge and on said vertically disposed gas collecting chamber for detachably receiving the peripheral edge of said upper roof structure.

2. A floatable roof for sewage digestive tanks comprising a substantially Vhorizontally extending cover, said cover having a vertically extending peripheral edge, a vertically disposed gas collecting chambervat the center of said roof and having open communication with said tank, an upper roof structurey carried by said cover in spaced confronting relation, said upper roof structure consisting of a plurality of prefabricated panel sections each comprising agtop plate -and an inner load carrying bottom plate, means for spacing `s ,aid IOP plate and said bottom plate in a parallel plane withrespect to each other, insulation moans carried between the top plate and the bottom plato, the said topplote being of a Sil@ greater than said bottom platea-solas to provide an ovor-lapping portion along one side and bottom edge thereof, said over-lapping portion providingapover for the connection points between said panelled ,sections means carried by said cover for supporting said upper roofstructure in spaced floating relation, clip means carried by said upper roof structure for detachably connecting itself to said supporting means, and means on said vertically extending peripheral edge and on said vertically disposed gas collecting chamber for detachably receiving the peripheral edge of said upper roof structure.

3. A floatable roof for `sewage digestive tanks comprising a lsubstantially horizontally extending cover, said cover having a vertically extending peripheral edge, a vertically disposed gas collecting chamber at the center of said roof and having open communication with said tank, an upper roof structure carried by said cover in spaced confronting relation, -said upper roof structure consisting of a plurality of prefabricated panel sections each comprising a top plate and an inner load carrying bottom plate, means for spacing said topplate and said bottom plate in `a parallel plane with respect to each other, insulation means carried between the top plate and y the bottom plate, the said top plate being of a sizeV greater than said bottom plate so as to provide an over-lapping portion along vone side and bottom edge thereof, said overlapping portion providing a cover for the connection points between said panelled sections structural trusses carried by said cover for supporting said upper roof .structure in spaced floating relation, clip means carried by said upper roof structure for detachably connecting itself to said structural trusses, and means on said vertically .extending peripheral edge and on said vertically disposed gas collecting chamber -for detachably ,receiving the :peripheral edge of Y,saildulvaper roofrstructure.

References Cited in the le of this patent UNITED STATES PATENTS 2,295,103 Friedly Sept. 8, 1942 2,324,710 Livar July 20, 1943 2,605,014 Wiggins et al. -..1--- July 29, 1952 2,616,586 Lamb Nov. 4, 195,2

FOREIGN PATENTS 18,172 Australia June 26, `1934 

